html,
body {
    margin: 0;
    font-family: "Microsoft YaHei", sans-serif;
    background: #fafafa;
    color: #333
}

.box {
    width: 90%;
    margin: 40px auto;
    background: #fff;
    border: 1px solid #e5e5e5;
    border-radius: 8px;
    overflow: hidden;
    padding: 20px
}

h1 {
    color: #ff6633;
    margin: 20px 0;
    text-align: center
}

/* 底部按钮组 */
.footer-btn {
    text-align: center;
    margin-top: 30px
}

.footer-btn button {
    margin: 5px;
    padding: 8px 20px;
    background: #ff6633;
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer
}

.footer-btn button:hover {
    background: #e55a2b
}

/* 按钮组 */
.btn-group {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
    border: 1px solid #ff6633;
    border-radius: 6px;
    overflow: hidden
}

.btn-tab {
    flex: 1;
    padding: 10px 0;
    background: #fff;
    color: #ff6633;
    border: none;
    cursor: pointer;
    font-size: 15px;
    border-right: 1px solid #ff6633
}

.btn-tab:last-child {
    border-right: none
}

.btn-tab.active {
    background: #ff6633;
    color: #fff
}

/* 内容区 */
.content {
    border: 1px solid #e5e5e5;
    border-radius: 6px;
    overflow: hidden
}

iframe {
    width: 100%;
    height: 500px;
    border: none
}